Opposed piston engine developed 140 years ago

Opposed piston engine developed 140 years ago

There’s nothing new about opposed piston diesel engines. An industrial electrician I’ve known for 50 years worked on one of the giant engines at Churchill, Man., a few years ago.

Pat Barry recalls the engine was in a 60-foot tugboat used in pushing and pulling grain ships around at the terminal.

“This was a three-cylinder, six-piston engine that stood taller than me,” said the six-foot, six-inch Barry.

The 12-inch diameter output shaft on a 1950s model Fairbanks Morse engine needed a new keyway. The tugboat owners deemed that removing the engine and hauling it south for the job would waste too much time, so they began scouring machine shops looking for a person with a machine who could do the work on-site in the tug.

They found Barry at King’s Electric in Winnipeg. Barry brought a cutting device that resembled a portable milling machine that clamped firmly to the shaft. Multiple passes with the cutter created a foot-long keyway that the key firmly fit.

One of the first opposed-piston engines was the 1882 Atkinson differential engine, according to Old Machine Press. It had a power stroke on every rotation of the crankshaft.

It was not a commercial success. In 1898, a 600 horsepower, two-stroke, opposed-piston engine was installed at the Hoerde ironworks.

An early opposed-piston car gasoline engine was produced by the French company Gobron-Brillié around 1900. Four years later, a Gobron-Brillié car set a world ground speed record of 152.5 km/h (95 mph).

The first diesel engine with opposed pistons was a prototype built at Kolomna Works in Russia.

In 1932, the Junker aircraft company in Germany introduced the Jumo diesel 205 two-stroke with six cylinders and 12 pistons in an opposed configuration. This design required two crankshafts, one at the bottom of the cylinder block and the other at the top, geared together. The pistons moved toward each other during the operating cycle.

Two cam-operated injection pumps per cylinder fed four nozzles per cylinder.

Fairbanks Morse took an interest in Jumo 205 and acquired a licence to produce such engines in the United States. The opposed-piston design offers some advantages over conventional engines by having fewer parts, no cylinder head, improved thermal efficiency and more power for a given size and weight.

Fairbanks Morse used the Jumo design to develop its own line of opposed-piston diesel engines, one of the first being the Model 38. This was a two-stroke vertical engine with two crankshafts linked by a gear train.

In its original form, the engine had eight cylinders, displaced 8,042 cubic inches, and produced 1,200 h.p. at 720 rpm.

In 1934, the United States Navy ordered eight of these engines for Porpoise-class submarines.

By 1937, Fairbanks Morse 38 design was offered in cylinder numbers from four to 12, with power up to 1,600 h.p. Approximately 1,650 38D8 engines were built during the Second World War. Although changes have been incorporated over the years, the 38D8 remains in production today.

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